Cursor stealing focus - fix

[rozyczko]

Sorry for two birds with one stone.

Enhancement - a footer element, similar in scope to "Continue" button on the bottom of the Basic Sideview.
I think this fits in the general library, in order to allow for other buttons to reside at the bottom of the sideview, which we don't want to be affected by scrolling of the elements above.
In ERA, I want the "Fit" button to be always visible, not when the parameter table is scrolled up.

Additionally, a small fix is added such that moving the cursor doesn't steal focus from the edited parameter cell.
It is doing it now.

[AndrewSazonov]

Is this still valid, or did we decide to use the same approach as in EasyDiffraction for adjusting the table size in the sidebar instead?

[rozyczko]

The footer issue can be fixed in the app. Removed relevant changes.
The hover issue needs addressing here, unless some other PR from Ales is covering this.

[seventil]

Just have two comments to make, first is what I'd think a bug in this implementation: when you click on one field, it holds hover higlight, and if the tableview looses focus, the hover is reset and then works properly. But if I make a second click on another textinput in the same view, the first textinput still holds the highlight.

Second thing is just FYI: how I solved it for my listview. The focus is stolen onHovered, right, but it is actually currentIndex that does it. currentIndex is essentially a selection, that tableview rewires for hover highlight so it makes sense that selector moves focus on just hover. I got rid of currentIndex binding for listview, seems to be working OK